The concept of the Alcohol Dependence Syndrome has been influential in the field of alcohol studies in the 1980s. The Severity of Alcohol Dependence Questionnaire (SADQ) is one of a generation of alcohol problem scales developed to measure degree of dependence rather than presence or absence of 'alcoholism'. This paper describes the development of a form of the SADQ for community samples of drinkers (SADQ-C) and its relationship to a brief scale designed to measure impaired control over drinking. In a sample of 52 problem drinkers, SADQ and SADQ-C correlated almost perfectly (r = 0.98). In a larger sample of 197 attenders at a controlled drinking clinic, Principal Components Analysis revealed one major factor accounting for 71.7% of the total variance. High internal reliability was indicated with a Cronbach's Alpha of 0.98. Application of this instrument in a random survey of Western Australian households is then described. It was necessary to remove items relating to 'reinstatement of dependence' for this sample. A single major factor was identified by principal components analysis, accounting for 69.1% of the total variance. In both the clinic and the community samples SADQ-C scores correlated highly with Impairment of Control scores. The findings are interpreted as supporting the view that there is a single dimension of alcohol dependence upon which all persons who drink alcohol with any regularity may be located.